Improvement in pianos



G. CADDIGK.

Piano.

Pat'ent ed April 16 fiuss us NJEYERS, PHOTO-LlTHcGRAFl-IER, WASHINGTON. u c.

UNITED STATES PATENT OEEIoE.

GEORGE OADDIOK, OF ALLEGHENY, PENNSYLVANIA.

IMPROVEMENT IN PIANOS.

Specification forming part of Letters Patent No. 202,408, dated April 16, 1878; application filed January 16, 1878.

To all whom it may'concern:

Be it known that I, GEORGE OAnnrcK, of Allegheny, in the county of Allegheny and State of Pennsylvania, have invented a new bars composed of iron, steel, or other metal,

with screw-threaded sockets on their ends. These are placed between the sound-board and strings of the instrument, pass through the bridge, and abut against the wrest-plank and plate plank, having a metal bearingbar, provided either with bosses to receive the ends of the tubes or equivalent devices intervenin g between the ends of the tubes and said wrest and plate planks. The tubes serve to resist the pull of the strings, and also to distend the sound-board.

The object of the invention is to obtain a light yet staunch resistance to the pull of the strings, and to provide a means of regulating the sound-board to its proper tension, so as to produce the best volume and quality of sound, which is accomplished by adjusting the screw-threaded sockets on the tubes un til the desired distension of the sound-board is produced. After this distending the plate plank is secured to the frame.

The method of distending may be after the sound-board is inserted into the wrest-plank and plate-plank, and before securin g the same to the back frame, or, secure the wrest-plank to the frame, insert the lower edge of the sound-board into the groove in the plateplank, place in the tubes, then insert the upper edge of the sound-board into the wrestplank, and distend the same before securing the plate-plank to the frame.

Figure l is a plan view of a device embodying my invention. Fig. 2 is a view of the same in section.

A is the back frame or stanchions, to the front of which is secured the wrest-plank B and plateplank O. D is the sound-board, (the fiber running perpendicular,) one end of which is let into the plate-plank, and the other is let into the wrest-plank. E are the tubes, having screw-threaded sockets on their ends. G is an iron bar, or equivalent, intervening between the wrest-plank and tubes, as also between the plate-plank and tubes, and having bosses I. H is a metal plate, with flange, to which the strings of the instrument F are attached in the usual way. It is firmly bolted to plate-plank O. K are the bridges, over which the strings F pass to tuningpins in the wrest-plank. J are screw-threaded pins, screwed through plate H and into tubes E, and while the pins hold the iron plate at proper distance from the tubes, the tubes are thereby kept straight, and will the better resist the strain.

By the above arrangement of the pins J it is apparent that a proportion of the pull of the strings is transmitted to the tubes, whereby a much lighter iron plate may be used than heretofore, which will very materially reduce the weight of the piano.

It is evident thatthe tubes, being placed between the sound-board and strings, act as a center, so that the. pull of the strings maintains the distension of the soun d-board against extension and contraction by atmospheric changes.

Having thus described my invention, I claim as new and desire to secure by Letters Pat ent- 1. A number of tubes or bars, composed of iron, steel, or other metal, placed between the sound-board D and strings of the instrument to resist the strain of the strings, and having screw-threaded sockets on their ends for distending the sound-board D, substantially as shown and specified.

2. The screw-threaded pins J, screwed through the plate and into the tubes, for the purpose set forth.

In testimony that I claim the foregoing improvements in upright pianos, as above described, I hereunto set my hand this 3d day of January, 1878.

GEORGE OADDIOK.

Witnesses:

J OHN MGKAIN, JOHN J. McOoRMroK. 

